Driver means for magnetic elements



Dec. l5, 1959 E. J. SCHUBERT 2,917,639

' DRIVER MEANS FOR MAGNETIC ELEMENTS Filed Dec. 20, 1957 Recorder l Control \|5 aan l A s B+ Bl* e3-1 l2 ,u N

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2t Output C D e 9 l, l5` B- t8 I9 Recorder h 1- Control 28 r ;,N [so 1 81.6' 26o l Output B+ 7 24 25 2 6'1 27 1i B`-"""' o LLZGb 29 f N Output Recorder ,-|5 A B Control L -i/gg l22h:

l B+.: E,LIBo-I- |2 v n Output .5.1 I4 L B J-*o-lt 6\ f 7 n I3b `B- sl le ,n J 2| 25 33^ 4 3 l Input Output 2 T 5 32 ua D |9 e s Recorder 28 "8:50 Control |5 g 29 Output 26a l i \soa LAK-Q 24` 25 26'* 2" L -L-/N B17-'gwen WITNESSES INVENTOR Ernest J. Schubert ATTORNEY MEANS FOR MAGNETIC ELEMENTS Ernest J. Schubert, Berwyn, Pa., assigner to Westingbouse Electric Corporation, East Pittsburgh, Pa., a con poration of Pennsylvania Application December 20, 1957, Seriai No. 704,100

8 Claims. (Cl. 307-88) This invention relates to driver means for magnetic elements, and more particularly, to a transistor drive for aplurality of magnetic elements.

Itis presently a practice to provide separate transistor drive means for magnetic elements for the purpose of maintaining the transistor load within the rating. in some cases, it has been found to be satisfactory to drive ai plurality of magnetic cores from a single transistor where a constant current supply can be provided. However, constant Icurrent drive for transistors is impractical in ymany cases because of the voltages involved in the operation yof the transistor.

l `It is therefore an object of this invention to provide a circuitV arrangement capable of allowing a plurality of magnetic elements to be driven from a single transistor without thev necessity of a constant current source.

' It'isv another object of this invention to provide a transistor drive for a plurality of magnetic elements provided with a feedback circuit capable of maintaining the `transistor drive for the total switching period of the ckfvfesv even though the triggering impulses to the transistor maybe ofV veryshort duration.

It is another object of this invention to provide a constant Vload circuit for a transistor drive for magnetic lements during changing outputs.

Other objects, processes and characteristic features will become obvious as the description of the invention progresseis.'r 'l l 'I p "In practicing this invention, the circuit arrangement is around magnetic element applications, such as ring counters, complement-registers and selector switches where the total number of cores containing Ones and thosecontaining Zeros is equal and constant. In this yofcircuit'the transistor output can be coupled to a'sO many as 24 ycores for providing drive voltages for the vcores with the cores being arranged in parallel branches in which at least a Zero'and a One is positioned inl eachy branch. The cores are then provided with a feedback circuit either parallel o r series arranged to provide sufficient current during a sucient time duration maintain the, transistor in conductiony for a time period sufiicient to allow the cores to be driven from one saturatinn to the other.

Figure l shows a transistor drive for magnetic cores involving the use of a series feedback circuit.

"Fig, 2 is a diagrammatic showing of a transistor havingv a plurality of parallel output paths for driving magnetic cores in'wvhich a parallel feedback circuit is used. l"In each of the several views, similar parts bear like reference characters.`

The driver circuit of Fig. 1` utilizes a transistor 1 having an emitter 2, a collector 3 and a base 4. The transistor 1 is connected to a trigger source to apply a controlimpulse to the base 4 throughV a diode 5` for assuring proper` decoupling of the trigger source from feedback'loop. The collector 3, of the transistor 1 isprovided with PdallelA circuits having4 input` windings 6, 7, 8 and 9 positioned on the saturable cores A, B, C

lUnited States Patent O and D, respectively. The input windings ,6 and 7 are placed in series and connected to the collector 3 through a conductor and to a negative terminal B- of a source of power .such as a battery, not shown, having center terminal N grounded. Similarly, the input windings 8 and 9 are connected in series and between the collector 3 and the negative terminal B- of the source of power. yln order to provide a balanced load circuit for the transistor 1, it is necessary that the pair of cores A, B and the pair C, D, respectively, are set in opposite Vstates prior to the operation of the transistor so that only one of the pair of cores A, B or C, D will be in the state One. This arrangement is accomplished through the use of the control windings 12 and 11 mounted on the cores A and B, respectively, and wound in opposite sense so that a voltage of one polarity being applied against the cores in series would cause the insertion of a One in one core and of a Zero in the other core.

The control windings 12 and 11 may be connected to any source i.e., a control circuit having parallel control paths between B-land ground, and B- and ground where ground is the center tap point on the battery. The parallel paths may be arranged through the switches 13 and 14 controlled by a control element such as recorder control 15 in such a manner that only one of the parallel paths can be completed at any one time. For example, when the switch 13 is shown in one of its eXtreme positions, such as shown in the drawing of Fig. 1, a path is complete from B- through the contact member 13b of the switch 13 through the control windings 12 and 11 connected in series to the ground point end with the switch 13. In this position, the contact member 13a acts to interrupt the path from the plus terminal of the source of power through the contact member 14 and windings 12 and 11 connected in series to ground. Even though the contact member 14 may be closed, the switch member 13a would maintain the circuit in an interrupted condi` tion. If the switch 13 was reversed, it can be seen that the path from B- to N through the input windings 12 and 11 would become interrupted and the path from B-lto N through the control windings 12 and 11 would be prepared for completion upon the operation of the switch 14. It is therefore possible to insert information in the core A and the complement into B by means of the windings 12 and 11.

In order to insure that the control impulses delivered to the transistor 1 over its trigger circuit connectedlto the base 4 are independent from the switching time of the cores A and B, a feedback circuit comprising the windings 16 and 17 placed about the cores A and B, respectively, is provided. The windings 16 and 17 are connected in the circuit originating at ground passing; through a pair of windings 18 and 19, to be explainedf hereinafter, on the cores C and D. The windings 16 and 17 are connected in series and a diode 20 assuring proper decoupling is maintaining transistor conduct-ion during this period to the base 4 of die transistor. With this circuit, it can be seen that any negative induced in the cores A and B would be delivered through the diode 20 to the base member 4 of the transistor 1. The magnetic cores A and` B are provided with output coils 21 and 22, respectively, on the output lines 23,- and` 23a, respectively, for delivering output impulses to be utilized in any desirable manner. i

When a pulse or binary input is applied to the transisftor 1 it will be fed4 to the input windings 6 and 7. can result in an output on conductor 23 or conductor 23a. The output is. selectively fed through one of. these. conductors depending upon the position of switches- 1;3 and 14 which are actuated, by the; recorder controly 15,.

ings 8 and 9 which can similarly result in an output on conductor 30 or conductor 30a depending on the position of switches 26 and 27. As explained before, the windings 8 and 9 of the cores C and D are connected in parallel with the input windings 6 and 7 of the cores A and B and are therefore energized at the same moment as the windings 6 and 7. The cores C and D are also provided with control windings 24- and 25 which are similar to the control windings 12 and 11 of the cores A and B. The windings 24 and 25 are also controlled over parallel circuits including the positive and negative terminals of the battery to the neutral terminal N of the battery with the circuits being completed over a switch 26 having contacts 26a and 26]; in the positive and negative branches of the parallel circuit, respectively, and operable in a manner identical with the operation of the switch 13 described hereinafter. The circuit including the positive terminal B-lof the battery to the center terminal battery N also includes a control switch 27 controlled over a control mechanism such as the control mechanism indicated above to provide the proper output response desired. The cores C and D are thus explained in a manner similar to the core A and B with only one of the cores set to One at a time. lt can be seen, therefore, that additional parallel paths such as this can be provided to the maximum load limit of the transistor 1 as well as each parallel path connected to the collector 3 of the transistor 1 includes equal num- 4ber of magnetic cores containing Ones and Zeros.

It is pointed out that the cores C and D are also provided with output windings 28 and 29, respectively, on the output conductors 30 and 39a, respectively, for delivering output impulses to be used in any desired manner. The cores C and D are also provided with feedback windings 18 and 19 previously mentioned as connected in series with the feedback windings 16 and 17 of the cores A and B. Voltage of proper polarity picked up by any one of the windings 16 through 19 would therefore provide adequate feedback energy to maintain the transistor 1 in conduction for a period sutiiciently long to allow the cores A and B or C and D to complete their switching.

The driver circuit shown in Fig. 2 is identical with the circuit shown in Fig. l with the exception that the feedback circuit for the cores A and B and C and D include parallel connected circuits rather than a series connected circuit as shown in Fig. 1. For example, the windings 16 and 17 of the cores A and B are connected in parallel with the windings 18 and 19 of the cores C and D with the junction provided between windings 16 and 17 being polarized by the diode 31 and the junction of the windings 18 and 19 being polarized by the diode 32 with the two circuits connected. in parallel to the conductor 33 which is in turn connected to the base member 4 of the transistor 1. It can be seen that in this case also, energy delivered toany one of the windings 16 through 19 is placed on the base member 4 of the transistor 1 and is utilized to maintain conduction of the transistor until the core functions are completed.

Since numerous changes may be made in the abovedescribed construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

l. A driver circuit for magnetic elements comprising a transistor having emitter, collector and base electrodes, a plurality of saturable magnetic elements each having input and control windings, said input windings being connected in series and to said collector, said control windings being positioned on said elements so that energy of one polarity only drives one-half of the said plurality of magnetic elements to one saturation and energy of the opposite polarity drives the other half of said magnetic elements to saturation, and feedback means for maintaining said transistor in conduction state following a trigger pulse of short duration on said base.

2. A driver circuit for magnetic elements comprising a transistor having emitter, collector and base electrodes, a plurality of saturable magnetic elements each having input and control windings, said input windings being connected in series and to said collector, said control windings being positioned on said elements so that energy of one polarity only drives one-half of the said plurality of magnetic elements to one saturation and energy of the opposite polarity drives the other half of said magnetic elements to saturation, and feedback means for maintaining said transistor in conduction state following a trigger pulse of short duration on said base, said feedback means comprising windings on said magnetic elements.

3. A driver circuit for magnetic elements comprising a transistor having emitter, collector and base electrodes, a plurality of saturable magnetic elements each having input and control windings, said input windings being connected in series and to said collector, said control windings being positioned on said elements so that energy of one polarity only drives one-half of the said plurality of magnetic elements to one saturation and energy of the opposite polarity drives the other half of said magnetic elements to saturation, and feedback means for maintaining said transistor in conduction state following a trigger pulse of short duration on said base, said feedback means comprising windings on said magnetic elements, said windings being connected in series.

4. A circuit for magnetic cores comprising a transistor having emitter, collector and base electrodes, a plurality of saturable magnetic cores, each having input and control windings, said input windings being connected in a plurality of series paths connected in parallel to said collector, said control windings being positioned on said cores so that energy of one polarity only drives one-half of the cores of the series connected input windings of each parallel path to saturation and energy of the opposite polarity drives the remaining cores to saturation.

5. A circuit for magnetic cores comprising a transistor having emitter, collector and base electrodes, a plurality of saturable magnetic cores, each having input and control windings, said input windings being connected in a plurality of series paths connected in parallel to said collector, said control windings being positioned on said cores so that energy of one polarity only drives one-half of the cores of the series connected input windings of each parallel path to saturation and energy of the opposite polarity drives the remaining cores to saturation, anl feedback means for maintaining said transistor in conduction following initial conduction by an input pulse on said base.

6. A circuit for magnetic cores comprising a transistor having cutter, collector and base electrodes, a plurality of saturable magnetic cores, each having input and control windings, said input windings being connected in a plurality of series paths connected in parallel to said collector, said control windings being positioned on said cores so that energy of one polarity only drives one-half of the cores of the series connected input windings of each parallel path to saturation and energy of the opposite polarity drives the remaining cores to saturation, and feedback means for maintaining said transistor in conduction following initial conduction by an input pulse on said base, said feedback means comprising windings on said cores.

7. A circuit for magnetic cores comprising a transistor having emitter, collector and 'oase electrodes, a plurality of saturable magnetic cores, each having input and control windings, said input windings being connected in a plurality of series paths connected in parallel to said collector, said control windingsv being positioned on said cores so that energy of one polarity only drives one-half of the cores of the series connected input windings of each parallel path to saturation and energy of the opposite polarity drives the remaining cores to saturation, and feedback means for maintaining said transistor in conduction following initial conduction by an input pulse on said base, said feedback means comprising windings on said cores, said windings being connected in series.

8. A circuit for magnetic cores comprising a transistor having emitter, collector and base electrodes, a plurality of saturable magnetic cores, each having input and control windings, said input windings being connected in a plurality of series paths connected in parallel to said collector, said control windings being positioned on said cores so that energy of one polarity only drives one-half of the cores of the series connected input windings of each parallel path to saturation and energy of the opposite polarity drives the remaining cores to saturation, and feedback means for maintaining said transistor in conduction following initial conduction by an input pulse on said base, said feedback means comprising windings on said cores, said windings being connected in series parallel arrangement.

Reerences Cited in the le of this patent UNITED STATES PATENTS 2,748,274 Pearlman May 29, 1956 2,781,504 Canepa Feb. 12, 1957 2,849,673 Hubbard Aug. 26, 1958 

